NO LUK - Protect your privacy
You are sitting in a crowded place and you are writing private messages, but people can see your display and read your messages while you are writing.
NO LUK is the answer, it protects your privacy. Stop them watching on your smartphone display.
You have to look at your bank account in a crowded place like in a train, and people can look at your display while you are entering your password. With NO LUK you can hide the display and enter safely your data.
In a train / bus
You are staying in the crowded train and you are writing posts in facebook. People around you can see your display, follow your posts and see your private photos. With NO LUK you can hide your display.
You are sitting in a meeting and you got an important message, which you have to answer. But also you want to be respectful, so you don't want them to see, that you are writing private messages. With NO LUK you can hide your display and no one near you can read or identify your action.